1. Technical Field The invention generally relates to restraints of cargo, particularly to cargo bars used in truck bodies to prevent cargo from moving while in transportation.
2. Related Art
The cargo loaded in a truck body or container usually needs a cargo bar to prevent it from scattering or impacting. A cargo bar is a retractable rod whose two ends are separately provided with two rubber pads for bearing against the truck walls (or the floor and ceiling).
U.S. Pat. No. 5,443,342 discloses a typical ratchet type cargo bar. This cargo bar is axially provided with a toothed rail on a telescoping rod. The toothed rail pivotally connects a handle. The pivotal end of the handle is provided with a ratchet wheel engaging with the toothed rail. By the reciprocation of the handle and unidirectional driving of the ratchet wheel, the toothed rail only can be unidirectionally moved to adjust length. However, this arrangement requires a ratchet wheel, which has complicated structure and expensive cost. On the other hand, lengthen the telescoping rod completely depends on the engagement motion between the ratchet wheel and toothed rail. No matter how long the length to be lengthened is, the engagement motion is always needed. Thus, both the toothed rail and ratchet wheel require prolonged engagement. Additionally, the conventional toothed rail is made of cast aluminum or cast copper, so they tend to be fractured because of insufficient strength. As a result, this kind of cargo bar does not have great durability. Moreover, their manufacturing costs are pretty high.